Combined imaging technology may improve breast cancer diagnosis
MedWire News: A combined technique that incorporates optical and X-ray imaging may help clinicians better distinguish malignant lesions from benign lesions in the breast, US researchers report.
"By co-registering optical and X-ray data, radiologists are able to map suspicious findings and analyze the functional characteristics of those areas," said lead researcher Qianqian Fang (Massachusetts General Hospital, Boston).
Fang and team developed a combined optical/x-ray imaging system capable of obtaining both functional optical and structural x-ray images of the breast.
The system used digital breast tomosynthesis - a three-dimensional application of digital mammography - and diffuse optical tomography, which measures total hemoglobin concentration (HbT), oxygen saturation, and other cellular characteristics based on how light from a near-infrared laser is absorbed and scattered within tissue.
In the present study, the researchers evaluated the imaging system in 189 breasts from 125 women with a mean age of 56 years.
In total, 138 breasts had negative findings and 51 had lesions that were subsequently biopsied. The biopsies revealed 26 malignant and 25 benign lesions.
In the 26 malignant tumors, HbT was significantly greater than that in the normal fibroglandular tissue of the same breast. Solid benign lesions (n=17) and cysts (n=8) had significantly lower HbT contrast compared with the malignant lesions.
In addition, oxygen saturation levels were significantly lower in cysts compared with all other tissue types.
"Although cysts are easy to diagnose using ultrasound, distinguishing cysts from malignant or benign lesions during a mammogram would save women the anxiety and costs associated with a second procedure," Fang said.
The researchers note that since the number of lesions involved in their study was low: "The results reported here are rather preliminary and merely serve as an early indication of the diagnostic potential of the proposed method."
However, Fang concluded: "By providing additional differentiation of malignant and benign lesions, combined optical and X-ray imaging could potentially reduce unnecessary biopsies."
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By Laura Dean